07 Public Goods（课件）- 《财政与金融》同步教学（人民大学·第五版）

7 7.1 Optimal Provision of Public Goods 7.2 Private Provision of Public Goods 7.3 Public Provision of Public Goods 7.4 Conclusion Public Goods 1 of 30 1 7 Public Goods: Trash Collection in Dhaka, Bangladesh Why don’t people pay to have their neighbor’s trash collected? No one wants to pay, but everyone wants someone else to pay. Private trash collection, financed by a voluntary fee paid by neighborhood residents, faces the classic free rider problem. Goods that suffer from this free rider problem are known in economics as public goods. of 30 C H A P T E R 7 ■ P U B L I C G O O D S 2 7.1 Pure public goods: Goods that are perfectly non-rival in consumption and are non-excludable. Non-rival in consumption: One individual’s consumption of a good does not affect another’s opportunity to consume the good. Non-excludable: Individuals cannot deny each other the opportunity to consume a good. Impure public goods: Goods that satisfy the two public good conditions (non-rival in consumption and non-excludable) to some extent, but not fully. Public Goods: A taxonomy of 30 C H A P T E R 7 ■ P U B L I C G O O D S 3 7.1 Defining Pure and Impure Public Goods Is the good rival in consumption? Is the good excludable? Yes No Yes Private good (ice cream) Impure public good (cable TV) No Impure public good (crowded sidewalk) Public good (defense) of 30 C H A P T E R 7 ■ P U B L I C G O O D S 4 7.1 How much of the public good should society provide? Markets will not provide the correct amount. To answer this question, start by reconsidering the market for a private good like ice cream cones. Ben and Jerry have different tastes for ice cream (ic), relative to the other good (c). How does the market aggregate their preferences? Optimal Provision of Public Goods of 30 C H A P T E R 7 ■ P U B L I C G O O D S 5 7.1 Ben and Jerry demand different quantities of the good at each price. The optimality condition for the consumption of private goods is written as: